Does the area of contact effect the frictional force . explain?

Aforce of 240.0 n causes an object to accelerate at 3.2 m/s2. what is the mass of the object?

What will a positive and a negative charge do if they are separated from each other?

With the simplified model of the eye, what corrective lens (specified by focal length as measured in air) would be needed to enable a person underwater to focus an infinitely distant object? (be careful-the focal length of a lens underwater is not the same as in air! assume that the corrective lens has a refractive index of 1.62 and that the lens is used in eyeglasses, not goggles, so there is water on both sides of the lens. assume that the eyeglasses are 1.90